Liverpool’s new German goalkeeper Loris Karius is set to be out for up to 10 weeks with a broken hand suffered in a 1-0 friendly defeat by Chelsea during the club’s U.S. tour, British media reported on Friday.

The 23-year-old, who joined the Reds for 4.7 million pounds ($6.22 million) from Mainz in May, accidentally punched team mate Dejan Lovren as he came out to clear a cross in Wednesday’s clash in Pasadena, California.

Karius carried on playing despite the damage to his hand sustained just before the hour mark but was sent for a scan on Thursday which confirmed the fracture.

He was flying back to Britain on Friday and is expected to need an operation, British media reported.

Liverpool manager Jurgen Klopp was expected to start with Karius in their Premier League opener against Arsenal on Aug. 14 but Belgian Simon Mignolet is now likely to keep his place.

They also have ex-Arsenal stopper Alex Manninger, 39, who joined the club on a free transfer from Augsburg last month.